A107037 Indices of squarefree Jacobsthal numbers.

1, 2, 3, 4, 5, 6, 7, 8, 10, 11, 12, 13, 14, 15, 16, 17, 19, 21, 22, 23, 24, 25, 26, 28, 29, 30, 31, 32, 33, 34, 35, 37, 38, 39, 41, 43, 44, 46, 47, 48, 49, 50, 51, 52, 53, 56, 57, 58, 59, 61, 62, 64, 65, 66, 67, 68, 69, 70, 71, 73, 74, 75, 76, 77, 78, 79, 82, 83, 85, 86, 87, 88

Offset: 1

Author

Paul Barry, May 09 2005

Keywords

• nonn

Links

• Amiram Eldar, Table of n, a(n) for n = 1..899

Crossrefs

Cf. A001045, A005117, A037918.

Programs

Mathematica

Rest[Flatten[Position[CoefficientList[Series[1/(1-x-2x^2),{x,0,100}],x],?SquareFreeQ]]] (* _Harvey P. Dale, May 27 2016 *)

Extensions

Offset corrected by Amiram Eldar, Feb 25 2024